Configuration Approaches; Parameters; Configuring Wred; Displaying And Maintaining Wred - HP 5830 Series Configuration Manual

Configuration approaches

On the device, WRED is implemented with WRED tables. WRED tables are created globally in system
view and then applied to interfaces.

Parameters

Before configuring WRED, determine the following parameters:
Upper threshold and lower threshold—When the average queue length is below the lower
•
threshold, no packets are dropped. When the average queue length is between the lower threshold
and the upper threshold, the incoming packets are dropped at the user-configured drop probability.
When the average queue length is above the upper threshold, all incoming packets are dropped.
Drop precedence—Parameter used in packet drop. Value 0 represents green packets, 1 represents
•
yellow packets, and 2 represents red packets. Red packets are preferentially dropped.
• Drop probability—Probability of dropping packets (in percentage). A higher value means a higher
drop probability.

Configuring WRED

In a WRED table, drop parameters are configured on a per-queue basis because WRED regulates
packets on a per-queue basis.
A WRED table can be applied to multiple interfaces. For a WRED table already applied to an interface,
you can modify the values of the WRED table, but you cannot remove the WRED table.
To configure and apply a queue-based WRED table:
Step
1. Enter system view.
2. Create a WRED table
and enter its view.
3. Configure the WRED
parameters.
4. Enter interface view.
5. Apply the WRED table
to the interface.

Displaying and maintaining WRED

Task
Display WRED configuration
information on an interface or all
interfaces.
Command
system-view
qos wred queue table table-name
queue queue-value [ drop-level
drop-level ] low-limit low-limit high-limit
high-limit [ discard-probability
discard-prob ]
interface interface-type interface-number
qos wred apply table-name
Command
display qos wred interface [ interface-type
interface-number ] [ | { begin | exclude |
include } regular-expression ]
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Remarks
N/A
N/A
Optional.
By default, low-limit is 10,
high-limit is 80, and discard-prob is
15.
N/A
N/A
Remarks
Available in any view.